Apparatus for compressing air and other elastic fluids.



E. W. JONES.

APPARATUS rox coxrazssm AIR AND OTHER BLAs'rm FLUIDS.

APPLIUATIOH IILED FEB. 3.1913.

L Patented Aug. 18, 19M

2 SHEETB-BBEET l.

,/f ,Ar- I flb ala'es M 17727 rnew E. W. JONES.

APPARATUS FOB GOMPRBSSING AIB AED OTHER BLASTIO FLUIDE.

ArPLIoATlon Hmm rma.a,1a13.

Ll Patented Aug.18,191

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u se@ i Way/w; es @(2.5 Zzvezzifw UNITED sTATns EDWIN w. JONES, or IPsWIcH, EiveLANn- Speccatio of Letters Patent, I

resented Aug. 1s, 1914.

Application inea February' '3, ylei-'3. i serial No. 745,978'.

To all whom, it may concern:

,lie it known that I, EDWIN WALTER JONES, engineer, a British subject, residing at lpswich, Suffolk, England, have invented certain new and useful Improvements 4in Apparatus for Compressing Air and other Elastic Fluids, of which the following is a specification.

This invention relates to apparatus for compressing air or other elastic fluids, and its o ject is to increase the efficiency of such apparatus.

In multistage air compressors the cylinders of consecutive stages of compression are usually made of consecutively decreasing volumesand communicate-with each other through intcrcoolers, each cylinder being provided with an inlet and an outlet valve. The second or other intermediate cylinder works as follows:-At the beginning of the suction stroke of the piston the inlet valve opens and air from the intercoolcr on the ad# mission side enters the cylinder, while the outlet valve remains closed. At the beginning of the compression stroke the inlet valve closes, the air in the cylinder is compressed during the compression stroke, until the pressure is sufiieient to open the discharge valve against the pressure existing in the succeeding intercooler, when the delivery valve on the cylinder opens and the air enters the intercooler. Cooling therefore takes place before and after compression, but only to a slight extent during com- ,5 pression, for although in some cases the walls of the cylinder are to a certain extent cooled, such cooling is necessarily much slower than the cooling in pipes which have thin walls and a comparatively large cooling surface. The efficiency of multistage compressors and the speed at which they can be run depends largely on the rapidity and com leteness of cooling.

Accor ing to this invention the second or other cylinder of even number in the series is constructed without the usual inlet or outlet valves, the supplyand delivery-pipes communicating freely vwith the interior of the cylinder, so that the cylinder is always in free communication with the intercooler. Consequently during the compression stroke of the piston the said intercooler forms part of the compression space, the air is compressed therein, and consequently effective cooling takes place during compression,

'gsince the intercooler consists of thin Wallin-d pipes surrounded by water (though they mightfbe air cooled). It will be understood, thatat-*the end of the-compression stroke a portion of the air compressed and cooled in the intercooler Ienters the next cylinder in the series. During the subsequent return or suction stroke of the'piston the air remaining in the intercooler'expands against the piston, thereby returningvto it a portion of the work-'done during 'the compression stroke. By these means more rapid and effective cooling takes place.

The intermediate cylinder of a three-stage compressor maybe closed at both ends, one end (the vvalveless end) being connected through the intercooler' with the low-pressure cylinder and'also with the high-pressure cylinder, iny the manner described above, while theotherend is connected through a suction" valve with" the atmosphere and lthrough a discharge valve with the pipe leading from'the intercooler to the valveless endv of th'eiintermediate cylinder, the latter in addition to performing the ordinary function of a second` stage compressor, acting also as an auxiliary low pressure cylinder, whose output is added to the volume of air compresse in the first or low-pressure cylincler. This auxiliary low-pressure effect of the intermediate cylinder may be set in action, when required, according to the pressure of air in the receiver, by means of a device adapted to control the position of a valve, preferably the suction valve, of the said cylinder.

The motion of the pistons may be produced by a piston rod connecting the low-pressure with the intermediate piston and a lever and link mechanism acting on the said'piston rod, or it may be derived from a crank shaft and a pair `of connecting rods acting on the low-pressure and the intermediate piston, in which case the said pistons are constructed as trunk pistons and the intermediate cylinder is open at one end, or alternatively a guide may be provided for one or each of these cylinders, for example thel low-pres sure cylinder may have a trunk piston and connecting rod and the intermediate piston a connecting rod guide, so as to utilize both ends of the intermediate piston inthe manner described above.

In the accompanying drawings Figure l is a vertical section of a vertical three-stage compressor embodying my invention, Fig. '2 is a side view of the driving mechanism et right angles'to Fig. 1, Fig. 3 is a vertical section on a larger scale of a pair of valves of a double-acting intermediate cylinder provided with automatic regulation for the low pressure side.

in these drawings a is the low-pressure cylinder and c the high pressure cylinder placed axially above the low-pressure cylinder. Their pistons d and fare rigidly connected and single-actinfr. The intermediate cylinder b is mounted on the opposite side of the driving', mechanism and coaxial with. the other cylinders. As shown by the drawing, the sectional arca of the cylinder b is substantislllylessthan thatofcylindcr a, account being taken of the sectional areas of the piston rods. This is essential for the desired effect of. my invention. and in practice the volume of the low,` pressure cylinder is preferably largerthan that of the compression space comprising the intermediate cylinder and the intercooler.

The low pressure piston (Z is connected with the intermediate piston a by a piston rod g, on which is mounted a' cross head 7i set in motion by a pair of oscillating levers c' through the intermediary-of links,

rEhe air. which has been compressed in the cylinder a, provided with an ordinary inlet valve al and outlet valve n2 passes through the outlet Z into thepipes m of an intercooler and then through the admission port n directly into thelower end of cylinder L without the intervention of a valve. The upper end of the intereooler` con'ununicates with. the pipe go leadingT to the inlet valve q of the high-pressure cylinder o, and the air which has been compressed in the lutter escapes through an outlet controlled by a valve r into the discharge pipe a leading to a receiver t. rThe low-prcssure cylinder a has a suction valve f1.1 and a delivery valve o?, as mentioned above.

"ihe compression cylinders are secured to the side of a main frame or casting u.

it will be understood, that at the end or thedownward stroke of the intermediate piston e a portion ot the air compressed in the lower part of cylinder Z) and then cooled in the intcrcoolcr enters the cylinder c. During; the Subsequent return or upward stroke of the piston e the air remaining in the iutcrcooler expands against the piston, thereby returning to it a portion of the wori done during` the down stroke.

It will he noticed that the same system of cooling pipes serves alternately for conducting compressed air from the low-pressure cylinder as to the intermediate cylinder and. for conducting the air compressed in the latter to the high-pressure cylinder c, the intereooler forming part of the compression space.

The Iupper end ci the intermediate cylinder E, rse osed by a cover provided with a suction valve box b1 and a discharge valve box b2, from which a branch b3 leads to the air conduit extending from the pipe l, through the intcrcooler to the port n. The

upper side of the piston o and cylinder b may be rendered ineli'ective, that 1s to say,

the cylinder may be rendered single acting, preferably by keeping the suction valve bl open duringr the forward and backward strol-:e of the piston c, so that the pressure above the piston cannot become substanA tially higher, than that of the atmosphere, and thediseharge valve b2 will remain closed, or the suction valve may be held closed. thus allowing the air above the piston, which is not delivered through delivery valves to be alternately expanded and compressed. The suction pipe i; leading to the suction valve of the auxiliary cylinder may be provided with an ordinary valve o* which can he operated by hand, if it is desired to adjust the volume of auxiliary air admitted inde pendently of the receiver pressure.

If the valves of the upper end oiE the cylinder 7) act in the usual manner ol pump valves, the down-stroke of the pistou c draws air into the cylinder through the suction valve 7). and the subsequent 11p-stroke compresses the air which then escapes through the discharge valve 7F and branch pipe if" into the line of pipes connecting the cylinders In and rl`he compressed air discharged from the upper end of the cylinder Z1 is therefore added to that which flows from the cylinder (L to the cylinder b, and the upper part oi' cylinder b may thus be made to act as an additional lowpressure cylinder. rl`his auxiliary action of the cylindcr b may be made dependent on the pres sure of the air in the receiver 1f fed by the discharge pipe s of the high pressure cylin der o. Vi`he pressure iu the receiver will vary according to the volume of air abstracted from the same. for various purposes. if the volume is greater than that supplied during the same timo by the pipe a. the pressure will fall, in which case it is dcsiralile.y to increase. the supply of air by increasing the output of the low-pressure stage of the compressor. This may be done automatically by a device adapted to release the suction valve bl of the cylinder Y), when the pressure in thc receiver falls below a given minimum and which retains the valve bl in the open position, when the pressure in the receiver has risen to a given maximum. Any known device suitable for this purpose may be employed, and I make no claim to any speci-.il

construction, but may adopt. for instaura4 that shown by Fig. 3. ln this figure, Zi* indicates the suction valve, whose spindle is provided at the top with a collar Zit resting on n spring bf' adapted to hold the valvi in its closing position. into the valve boaV is screwed e easing,- Zi, which contains at the lOO i 'io llo top a vertically movable box b7 supported by a spring bs and containing a spindle b which terminates a short distance abovethe spindle ot the valve 71. rlhe upper part of the. casing L extends into a cap b1", provided at the top with a socket o for a pipe (not shown) communicating with the receiver'. duet ou leads from thc said socket to the interior ot the cap b1". The casing b has lateral openings communicating with the port bnopen tothe atmosphere, while, the porl lil communicates with the upper end of the cylinder b. In the position shown b v the drawing the valve b is free to ope-n and close. If the pressure in the receiver cxcceds the desired maximum, the spring box L* is forced down, and its spindle o orces down the valve b, so as to keep it open until the pressure in the receiver has dropped suflicicntly i'o` allowing the valve to close and act in the normal manner; o is thc delivery valve communiciding with the interior of I the cylinder /1 through the port b and with the, pipe b through the port b1".

`What l claim is:-

1. In an apparatus of the class described, thc combination of a single-acting low-pres sure cylinder and a single-acting high-pressure cylinder with an intermediate compression cylinder closed at both ends, one end being in constant communication with the outlet' valve oi the low pressure cylinder and with the inlet valve of the high pressure cylinder through an intcrcoolcr so that the 1ntei-cooler forms part of tho compression space at the intermediate compression stage, the cud of thc intermediate cylinder opposite to the constantly open end of the same having an inlet controlled by a suction valve and an outlet controlled by a discharge valve toward the conduit connecting the constantly open end of the intermediate c vlinder with the low pressure cylinder, so that while one. end of the intermediate cylinder receives air from the low-pressure cylinder, the opposite end muy act as an auxiliar)r low-pressure cylinder, substantially as dcscribed.

2. ln an apparatus of the class described. au intermediate compression cylinder closed at both ends, one end being in constant communication with the outlet valve of the low pressure cylinde and with the inlet valve of the high pressure cvlindcr through an intermoler so that the iutercooler forms part of the compression space at the intermediate compression stage` the end of thc intermediate cylinder opposite. to the constantly7 open end of the same having an inlet controlled by u suction valve and an outlet controlled by a discharge valve toward the conduit connecting the constantly open end of the intermediate cylinder with the low pressure, cylinder, so that while one end of the ri intermediate cylinder receives air from the low-pressure cylinder theuopposite end may act as an auxiliary 10W-pressure cylinder, and a device forvtemporarily rendering the auxiliary low-pressure cylinder ineiiective, substantially as described.

3. In an apparatus of the class described, the'combination of a single-acting low-pressure cylinde and a single-acting high-pressure cylinder with an intermediate compression cylinder closed at both ends, one end being in constant communication with the outlet valve of the low pressure cylinder and with the inlet valve of the high pressure cylinder through an intercooler so that the 1ntcrcooler forms part of the .compression s mee at the intermediate compression stage, the cnd of the intermediate cylinder opposite to the constantly open end of the same having a suction valve and a discharge valve communicating with the conduit connecting the constantly open end of the intermediate cylinder with thc low pressure cylinder, so that while one end of the intermediate cylinder receives air from the low pressure cylinder the opposite end may act as an auxiliary low pressure cylinder, a receiver for the air discharged from the high pressure c vlindcr, and a device adapted to control the position of one of thc valves of the intcrmediate cylinder according to the pressure in the said receiver substantially as described.

fi. Tn an apparatus of the class described, the combination of a single-acting low-pressure cylinder and a single-acting high-pres sure cylinder with a compression cylinder in constant communication at one end through an intcrcooler with the outlet valve of the immediately preceding compression cylinder and with the inlet valve of the iinmcdiatcly succeeding compression cylinder, so that the said intcrcooler forms part of the compression space whose volume, including that of the said intcrcooler, is less than that of the immediately preceding compression cylinder, substantially as described.

5. ln an apparatus of the class described, un intermediate compression cylinder in constant communication with the outlet valve of the low-pressure cylinder and with the inlet valve of the high pressure cylinder through an intercooler, so that the intereoolcr alternately serves to conduct air from the low-pressure to the intermediate cylinder, and from the intermediate cylinder to thc liiglrpressure cylinder, this intercoolcr 'forming part of the compression space of the intermediate compression stage, substantially as described.

G. ln a vertical compressor having an intermediate cylinder in constant communication at one end with the outlet valve of the low-pressure cylinder and with the inlet valve of the high pressure cylinder through an intercooler, the combination of a driving mechanism for the pistons, with a low-pressure cylinder and a. piston and a-high pres# throu` hthe intel-cooler, substentiall);y es desure cylinder and` piston arranged axially scribed.

behind each other on one side' of the driving lIn testimony `whereof I have herennto set mechanism, an4 intermediate compression my vhand infpresence .of two subscribing wit- 5 cylinder and piston situated on the opposite nesses.

side of the driving` mechanism in line with EDWIN W. JONES.

the other cylinders, an intercooler, nnd'pipe VWitnesses:

connecting the intermediate cylinder with JASPER Wn'rrnn,

the low and the high-pressure cylinders HENRY J. Bnoonwem..

Qopes e: this pltent may be obtained forme cents each; by nddromng the "Commissioner et'etente,

Washington, 3.6. 

